During the patent application process, I would like to correct the last drawing of the description on my own. How can I correct the drawing? (Just change a reference mark)

Similar to general amendments, there is one in the amendment, according to Article 51 of the Patent Law. . . Make corrections and check.

Before correction, write the reference mark as “12” or no reference mark.

After correction, write the reference mark as "111" or add the reference mark "111"

This has no fixed format, it only needs to show where you have modified it.